Identification of new sources for earliness and low grain moisture at harvest through maize landraces test-cross performance

Abstract

Early maturity is very important factor in the yield, grain moisture and plant density game, contributing to cost-efficient maize production. Landraces conserved in gene banks present a promising basis to enrich diversity of early maize breeding material. To start and speed-up the mobilization of currently scattered, unknown and underused maize genetic resources maintained in ex situ Maize Research Institute Zemun Polje gene bank collection, 63 landraces, as new potential sources of earliness and low grain moisture at harvest, were selected for evaluation of their test-cross performance with two divergent early testers. The majority of landraces (29), with prevailed flint type, exhibited heterosis for yield in crossings with BSSS-ID tester (102NS), where 20 top-crosses expressed grain moisture below defined threshold value (21.1%). The best performing landraces can be used as a starting-point of new pre-breeding programme for flint maize breeding material broadening. In parallel, nine landraces expressed simultaneous heterosis in crossings with flint tester (14NS), exhibiting grain moisture above threshold value. Simultaneous heterotic effect with two divergent inbred testers implied to the existence of an independent heterotic pool. These findings will contribute to broadening of maize breeding material for earliness and low grain moisture at harvest as important goals in maize breeding.